Approaches for a location aware client

ABSTRACT

Techniques for securing a client. Two or more varieties of location information for a client may be received. The present location of the client is determined using the two or more varieties of location information. A determination is made as to whether any of the varieties of location information were received during an immediately preceding bounded interval of time having a predefined length. A weight associated with each variety of location information that was received during the immediately preceding bounded interval of time is determined. The present location of the client is calculated using a weighted arithmetic mean for the varieties of location information that were received during the immediately preceding bounded interval of time.

CLAIM OF PRIORITY

This application is a continuation of U.S. non-provisional patent application Ser. No. 12/628,093, entitled “Approaches for a Location Aware Client,” filed by Jacques Lemieux et al. on Nov. 30, 2009, which is itself a continuation-in-part of U.S. non-provisional patent application Ser. No. 12/538,044, entitled “Secure Computing Environment Using a Client Heartbeat to Address Theft and Unauthorized Access,” filed by Anahit Tarkhanyan et al. on Aug. 7, 2009, the entire contents of both are incorporated by reference for all purposes as if fully set forth herein.

U.S. non-provisional patent application Ser. No. 12/538,044 claims the benefit of provisional application Ser. No. 61/188,404, entitled “Theft Deterrent and Secure Computing Environment,” filed by Gaurav Banga et al. on Aug. 8, 2008, the entire contents of which are incorporated by reference for all purposes as if fully set forth herein.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. 12/321,504 (now U.S. Pat. No. 8,346,234), entitled “Secure Platform Management with Power Savings Capacity,” filed by Gaurav Banga et al. on Jan. 21, 2009, the entire contents of which are herein incorporated by reference for all purposes as if fully set forth herein.

This application is also related to U.S. patent application Ser. No. 11/026,813, entitled “Secure Firmware Update,” filed by Andrew Cottrell et al. on Dec. 29, 2004, the entire contents of which are herein incorporated by reference for all purposes as if fully set forth herein.

This application is also related to U.S. patent application Ser. No. 12/538,040 (now U.S. Pat. No. 8,332,953), entitled “Receiving Policy Data from a Server to Address Theft and Unauthorized Access of a Client,” filed by Jacques Lemieux et al. on Aug. 7, 2009, the entire contents of which are herein incorporated by reference for all purposes as if fully set forth herein.

This application is also related to U.S. patent application Ser. No. 12/538,033, entitled “Secure Computing Environment to Address Theft and Unauthorized Access,” filed by Anahit Tarkhanyan et al. on Aug. 7, 2009, the entire contents of which are herein incorporated by reference for all purposes as if fully set forth herein.

This application is also related to U.S. patent application Ser. No. 12/613,440, entitled “Approaches for Ensuring Data Security,” filed by Anahit Tarkhanyan et al. on Nov. 5, 2009, the entire contents of which are herein incorporated by reference for all purposes as if fully set forth herein.

FIELD OF THE INVENTION

The present invention relates to approaches for performing an action, based on the present location of a computerized device, to protect resources of the computerized device from theft or unauthorized access.

BACKGROUND OF THE INVENTION

The use of portable computers, such as laptops or personal digital assistants (PDAs), has become very popular in recent years. Many people store personal information or documents, such as social security numbers, credit card information, and family photos, on their laptops. Also, the use of portable computers is quite common in the modern business environment. Corporate laptops and PDAs often contain confidential or sensitive business information, such as confidential documentation, e-mail addresses, bank accounts, and trade secrets.

It has been estimated that one laptop is stolen every 53 seconds. Theft of portable computers and intellectual property is an increasing concern. Unfortunately, only a very small percentage of stolen laptops are ever returned. Even if a stolen laptop is recovered, the confidential, sensitive, or personal data that was stored thereon may have been accessed by malicious parties, which is undesirable.

SUMMARY OF THE INVENTION

Approaches are described herein for performing an action, based on the present location of a computerized device, to protect resources of the computerized device from theft or unauthorized access. Embodiments of the invention may secure the resources of a wide variety of clients from theft or unauthorized access, even if the client is not presently in the possession of an authorized user or owner of the client.

According to an embodiment of the invention, a server may intermittently receive, from a client, location information, such as global positioning service (GPS) information, triangulation information, for the client, based on one or more Wi-Fi access points, and IP trace information for the client. A software component, executing on the server, may determine the present location of the client using the location information.

The server may determine the present location of the client using a variety of different approaches. For example, according to one approach, the server may determine whether global positioning service (GPS) information, triangulation information based on one or more Wi-Fi access points, and IP trace information for a particular client has been recently received over an interval of time. Thereafter, the server may determine a weight associated with each portion of the GPS information, the triangulation information, and the IP trace information received during the interval of time. The server may then calculate the present location of the client by determining a weighted arithmetic mean for the GPS information, the triangulation information, and the IP trace information received during the interval of time.

According to another approach for determining the present location of the client, the server may use an ordered sequence of different types of location information based on its perceived accuracy. For example, if it is determined that GPS information for a client has been received during a recent interval of time, then the server may use the location identified by the most recent GPS information as the present location of the client because GPS information is considered to be more reliable than other types of location information. On the other hand, GPS information may not always be available (for example, certain clients cannot obtain GPS information indoors), in which case the server may determine the present location of the client using triangulation information if it has been received during a recent interval of time, as triangulation information is more reliable than IP trace information. However, if both GPS information and triangulation information have not been received for the client during a recent interval of time, then the server may determine the present location of the client using IP trace information, as IP trace information is generally available.

The present location of the client may be made available for the owner of the client so the owner may monitor the current location of the client. For example, the present location of the client may be displayed on a map that is viewable by the owner of the client. Security policies may also be stored on the server which may enable the server to determine whether a command should be issued, from the server to the client, to perform an action based on the present location of the client. Additionally, the owner or authorized personnel monitoring the current location of the client may issue a command to the client, for immediate execution, to instruct the client to perform an action for purposes of protecting the client against theft or unauthorized access if the current location of the client is suspicious or otherwise suggestive that the client may be in possession of a malicious user.

In certain embodiment of the invention, the client itself may determine its own current location. After the determining its own current location, the client may follow a security policy that is described by policy data stored on the client. The security policy may instruct the client to perform an action based on the present location of the client. In this way, if the present location of the client is suggestive of a theft or unauthorized access, then one or more securities policies stored on the client may enable the client to protect itself from the theft or unauthorized access without any communication from the server. For example, one security policy may indicate that the client is to disable itself if the client is moved to an unauthorized area. As another example, another security policy may indicate that if a client is removed a certain distance from a corporate building, then the client should prompt the user to authenticate him or herself the next time the client is accessed. Security policies may be defined to instruct a client to perform a wide variety of actions based on the present location of the client for purposes of protecting the client against theft or unauthorized access.

The approaches described herein are not meant to describe all the embodiments of the invention, as other embodiments of the invention may differ in their operation compared to the illustrative approaches discussed in this section.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:

FIG. 1A is a high level block diagram of a system for protecting resources of a client from theft or unauthorized access according to an embodiment of the invention;

FIG. 1B is a block diagram of a system employing multiple servers according to an embodiment of the invention;

FIG. 2 is a high level block diagram of a server according to an embodiment of the invention;

FIG. 3A is a state diagram of an agent according to an embodiment of the invention;

FIG. 3B is a state diagram that includes additional details of the recovery state according to an embodiment of the invention;

FIG. 4 is a flowchart illustrating the functional steps of protecting resources of a client according to an embodiment of the invention;

FIG. 5A is a block diagram of the functional components of an operating system agent according to an embodiment of the invention;

FIG. 5B is a block diagram of the functional components of a BIOS agent according to an embodiment of the invention;

FIG. 6A is an illustration of a high-level approach for implementing examining modules according to an embodiment of the invention;

FIG. 6B is an illustration of another example of implementing examining modules according to an embodiment of the invention;

FIG. 7 is a flowchart illustrating the functional steps of communicating a policy from a server to a client according to an embodiment of the invention;

FIG. 8 is a flowchart illustrating the functional steps of securing a device according to an embodiment of the invention;

FIG. 9 is an illustration of a proximity condition according to an embodiment of the invention;

FIG. 10A is an illustration of server receiving location information over time according to an embodiment of the invention;

FIG. 10B is a flowchart illustrating the steps of protecting a client using a composite tracking algorithm (CTA) according to an embodiment of the invention; and

FIG. 11 is a block diagram that illustrates a computer system upon which an embodiment of the invention may be implemented.

DETAILED DESCRIPTION OF THE INVENTION

Approaches for protecting resources, stored on a computerized device, from theft or unauthorized access are described. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention presented herein. It will be apparent, however, that the embodiments of the invention presented herein may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention presented herein.

System Overview

FIG. 1A is a high level block diagram of a system 100 for protecting the resources of a client from theft or unauthorized access according to an embodiment of the invention. In an embodiment, system 100 includes clients 102, 104, and 106, server 120, and communications link 130. System 100 may be used to implement security policies to ensure that data stored on clients 102, 104, and 106 is protected from theft and authorized access. While FIG. 1A depicts three clients, there are no restrictions on the number of clients that an embodiment of the invention may have. Thus, embodiments of the invention may employ a single client or may employ a plurality of clients.

Clients 102, 104, and 106, as broadly used herein, refer to any computerized device which is capable of executing a BIOS and an operating system. Typically, a client will be a portable device, such as, for example, a laptop, a personal digital assistant (PDA), a cell phone, a game system (such as an Xbox available from Microsoft Corporation of Redmond, Wash. or a PlayStation 3 available from Sony Corporation of Park Ridge, N.J.), or a tablet computer, although there are no size or weight restrictions of what may constitute a client. Thus, a client may be implemented using a relatively large, immobile, or cumbersome computerized device, such as a vending machine, a computerized gasoline dispenser, or an automatic teller machine (ATM).

FIG. 1A depicts a detailed view of client 106. As illustrated by FIG. 1A, each client in system 100 executes a BIOS and an operating system. In an embodiment, each client includes an agent 110 (the client may have many other components in addition to agent 110). Agent 110 is a set of software components that operate to ensure that resources on the client upon which agent 110 resides are protected from theft and unauthorized access. Each agent 110 comprises two portions, namely a BIOS agent 112 and an operating system agent 114. BIOS agent 112 may be implemented by one or more software modules that execute in the BIOS of a client, while operating system agent 114 may be implemented by one or more software modules that execute in the operating system of the client.

In an embodiment, the BIOS of a client is firmware that is designed to be the first code executed by the client when the client is powered on. The initial function of the BIOS may be to identify, test, and initialize system devices such as the video display card, hard disk, floppy disk, and other hardware. The BIOS may prepare the client for a known state, so that software stored on media readable by the client can be loaded, executed, and given control of the client.

Among other functions that operating system agent 114 performs, operating system agent 114 monitors the resources of the client to ensure that the resources are not subject to theft or unauthorized access. After analyzing resources of a client for signs of theft, unauthorized access, or otherwise malicious activity, operating system agent 114 generates a heartbeat message that describes the operational state of the operating system agent 114, and thereafter sends the heartbeat message to BIOS agent 112. BIOS agent 112 may store security policies which the client receives from server 120. These security policies may instruct BIOS agent 112 to perform certain actions based on the content of the heartbeat message or whether the heartbeat message was received within an expected duration of time.

Server 120, as broadly used herein, refers to any mechanism capable of communicating with a client. Server 120 may be used to receive status information from clients as well as transmit policy data and commands to clients. For example, an owner of a set of clients may interact with server 120 to define one or more security policies, and thereafter server 120 may disseminate those defined security polices to the set of clients belonging to the owner.

In an embodiment, server 120 may be implemented as a server executing on a single computer system. In other embodiments of the invention, such as the embodiment depicted by illustration 180 of FIG. 1B, server 120 may be implemented using two or more servers that are executing on two or more different computer systems. In illustration 180, communications from clients, sent over communications link 130, may be received by application router 150, which may subsequently route the communication to an appropriate server for processing. As the number of clients in system 100 increases, it may be advantageous to implement server 120 using a plurality of different server instances to promote scalability and fault tolerance. Also, one or more servers depicted in FIG. 1B may be dedicated for a particular task, such as processing requests from a single entity or business. For example, to ensure availability and speed of processing, one or more servers depicted in FIG. 1B may be dedicated to communicate with clients associated with a particular entity, such as a business or a logical business unit of a company.

FIG. 2 is a high level block diagram 200 of a particular server 120 according to an embodiment of the invention. The server shown in FIG. 2 may correspond to server 120 depicted in FIG. 1A or one of the many servers (such as server 1, server 2, or server N) depicted in FIG. 1B. As shown by FIG. 2, in an embodiment, a server comprises a web interface 210, a runtime processing component 220, and data storage 230.

Web interface 210 refers to a functional component which enables a person to define and record one or more security policies that govern the behavior of clients in system 100. For example, an owner of one or more clients may use a web browser to record policy data that describes or defines a security policy, and thereafter may use the web browser to submit the policy data to web interface 210. Additional description about security policies, which may be defined and submitted to web interface 210, is provided below in the section entitled “Security Policies.”

Runtime processing component 220, as broadly used herein, refers to any mechanism for processing communications, such as state messages, received from clients as well as communicating security policies and/or commands to one or more clients in system 100. Runtime processing component 220 may be implemented using software that is configured to perform the runtime functions of server 120.

Data storage 230, as broadly used herein, refers to any mechanism for persistently storing data. For example, data storage 230 may be implemented using a database management system (DBMS) which comprises one or more database servers and one or more databases. In certain embodiments, data storage 230 may partially or wholly reside on a different machine than server 120. For example, server 120 may communicate over a communications link to a DBMS which implements the functions performed by data storage 230. In other embodiments, data storage 230 may be implemented locally at server 120.

Communications link 130 may be implemented by any medium or mechanism that provides for the exchange of data between a client, such as clients 102, 104, and 106, and server 120. Non-limiting, illustrative examples of communications link 130 include, without limitation, a network such as a Local Area Network (LAN), Wide Area Network (WAN), Ethernet or the Internet, one or more terrestrial, satellite or wireless links, and serial or parallel printer cables.

For a variety of reasons, the communications link 130 between a particular client, such as client 102, and server 120 may become intermittently unavailable. In particular, if the communications link 130 between client 102 and server 120 is implemented as a wireless link, at certain times the wireless link may be available and at other times the wireless link may not be available. For ease of explanation, in FIG. 1A communications link 130 is depicted between each client to server 120. However, those in the art shall appreciate that each client in system 100 may communicate with server 120 over a different type of communications link, e.g., client 102 may communicate with server 120 over a wireless link, client 104 may communicate with server 120 over a wired WAN, and client 106 may communicate with server 120 over a satellite link. Further, those skilled in the art will appreciate that, at times, a communications link between a particular client and the server may be unavailable at the same time that a communications link between another client and the server is available.

As shall be explained in further detail below, clients may use communications link 130 to transmit, to server 120, status messages, while server 120 may use communications link 130 to transmit, to one or more clients of system 100, security policies and/or commands. Having described an illustrative system 100 according to an embodiment of the invention, additional description about the possible operational states of agent 110 shall now be presented.

Agent States

Agent 110 operates to ensure that the resources of the client upon which agent 110 resides are protected from theft and unauthorized access. Agent 110 may operate in a variety of different states. Each operational state of agent 110 may reflect a different perceived threat level with respect to the theft and unauthorized access to resources of the client upon which agent 110 resides. To illustrate, consider FIG. 3A, which is a state diagram of agent 110 according to an embodiment of the invention. The operational state of agent 110 may change from time to time in response to differences in the threat level to the client as perceived by agent 110. The actions performed by agent 110 may differ based on the current operational state of agent 110.

Initially, agent 110 may start in an enabled state 310. Enabled state 310 is a state that indicates that the client upon which agent 110 resides is operating as expected and no threats of theft or unauthorized access have been detected by agent 110. Thus, if the intended user of a client is using the client, then the client should be in enabled state 310.

If agent 110 determines that a condition is satisfied which suggests it would be appropriate for the current user of the client upon which agent 110 resides to authenticate him or herself to agent 110, then agent 110 will enter degraded state 320. An example of such a condition may be the expiration of an amount of time (referred to as the “Time to Disable” or “TTD”) after which the current user of the client upon which agent 110 resides must authenticate him or herself to agent 110, e.g., by supplying a valid username/password combination or other such authentication credential. Degraded state 320 is a state that indicates that the client upon which agent 110 resides should prompt the user to authenticate himself to the client by submitting an authentication credential. If agent 110 is in degraded state 320, it does not necessarily follow that the client upon which agent 110 resides has been stolen or access in an unauthorized manner, degraded state 320 simply means that it is a possibility. Thus, in degraded state 320, agent 110 will attempt to determine whether the current user of the client is authorized to access the client by instructing the current user of the client to submit authentication credentials to agent 110. The amount of time that agent 110 should wait before entering degraded state 320 from enabled state 310 (the “TTD” time) may be based on a security policy or may be based on a random or semi-random duration of time determined either by agent 110 or by server 120.

If the current user of the client is able to authenticate himself as an authorized user of the client when agent 110 is in degraded state 320 after the expiration of a period of time, then agent 110 may, but need not, send a state message to server 120 to inform server 120 that the current user of the client has successfully authenticated himself to agent 110. The amount of time to allow the client to report and authenticate with server 120 when agent 110 is in degraded state 320 before agent 110 enters disabled state 330 is referred to as “Time to Trust” or “TTT.” The specific amount of time that corresponds to the “Time to Trust” or “TTT” time may change based on the security policies provided by server 120 and stored by BIOS agent 112 on the client, as the amount of time may be adjusted to reflect the sensitivity of the data stored by the client. A shorter TTT time provides greater security than a longer TTT time; however, a shorter TTT time also increases the risk that a legitimate user may be inconvenienced because the client entered disabled state 330 before the legitimate user could authenticate himself to agent 110. The TTT time may be established by recording the TTT time in a policy stored by BIOS agent 112 at the client. After the current user of the client authenticates himself as an authorized user of the client when agent 110 is in degraded state 320, agent 110 returns to enabled state 310.

When agent 110 is in degraded state 320, the user may be challenged to prove his identify at a certain frequency. The frequency at which the user is challenged to prove his identity when agent 110 is in degraded state 320 is referred to as “Time to Challenge” or “TTC.” As with the TTT time, the TTC time may be established by a policy stored by BIOS agent 112 at the client. The TTC time is independent of the TTT time. During the interval of time measured by the TTT value established by policy, the user of the client may be prompted to submit a valid authentication credential (for example, by submitting a valid operating system password) after each expiration of a period of time corresponding to the TTC time.

If the current user of the client is unable to authenticate himself as an authorized user of the client to agent 110, when agent 110 is in degraded state 320, then agent 110 will enter the disabled state 330. Disabled state 330 is a state that indicates that agent 110 has determined the client upon which agent 110 resides has been the subject to theft or an unauthorized access, and consequently, agent 110 disables the client. When a client is disabled, the client may immediately power down and become unable to boot. Thus, in an embodiment, if a malicious user attempts to operate a client having an agent 110 in disabled state 330, the malicious user will not be able to boot or otherwise use the client. In order for agent 110 to switch from disabled state 330 to enabled state 310, it may be necessary for an authorized user of the client, and/or personnel associated with the owner of the client, to supply, to agent 110, a key, digital certificate, authentication credential, or otherwise establish the fact that the client is in the possession of an authorized party.

If agent 110 determines that a condition is satisfied which might indicate the client has been compromised in some fashion when agent 110 is in enabled state 310, then agent 110 will enter recovery state 340. An example of such a condition may correspond to BIOS agent 112 not receiving a heartbeat message from operating system agent 114 after an expected period of time. Recovery state 340 is a state that indicates that agent 110 has detected a condition that suggests the client upon which agent 110 resides is stolen or being accessed in an unauthorized manner, but agent 110 is not yet ready to conclude so. In recovery state 340, the current user of the client may be provided an opportunity to authenticate him or herself to agent 110; additionally, agent 110 will monitor resources of the client when agent 110 is in recovery state 340, and if additional evidence surfaces to suggest that the client has been stolen or compromised, then agent 110 will enter disabled state 330. In recovery state 340, the user may be provided a limited opportunity to authenticate him or herself to agent 110. For example, as depicted in FIG. 3A, after three failed attempts by the user to authenticate him or herself, agent 110 enters disabled state 330. Note that the maximum number of failed attempts to allow before agent 110 moves from recovery state 340 to disabled state 330 may be established by a policy stored at the client. While FIG. 3A depicts a maximum number of three failed attempts before agent 110 moves from recovery state 340 to disabled state 330, this number is merely exemplary, as other embodiment of the invention may establish a different number of maximum failed authentication attempts before agent 110 moves from recovery state 340 to disabled state 330.

Embodiments of the invention may implement the operational states of agent 110 differently than that discussed above with reference to FIG. 3A. For example, certain embodiments may implement agent 110 such that one or more operational states discussed above with respect to FIG. 3A may contain two or more sub-states. To illustrate, consider FIG. 3B, which is a state diagram that includes additional details of recovery state 340 according to an embodiment of the invention. In the embodiment depicted by FIG. 3A, when agent 110 enters recovery state 340, agent 110 enters recovery sub-state 344 shown in FIG. 3B. When agent 110 enters recovery sub-state 344, agent 110 monitors the resources of the client and determines if the conditions that suggest a theft or unauthorized access has occurred improve, stay the same, or grow worse. If such conditions improve, then agent 110 may move to recovery sub-state 346 as shown in FIG. 3B, and if such conditions improve further, then eventually agent 110 enters enable state 310. However, if agent 110 is in recovery sub-state 344, and if conditions that suggest a theft or unauthorized access have occurred stay the same or grow worse, then a counter is incremented, and agent 110 remains in recovery sub-state 344. If the counter exceeds a threshold value, then agent 110 enters disable state 330. As the threshold value for the counter may be set by policies provided by server 120 and stored by agent 110, the operation of agent 110 (for example, how many opportunities agent 110 is provided before moving from recovery sub-state 344 to disable state 330) may be adjusted accommodate different balances between the need to provide a secure environment and the need to not be overly restrictive with user behavior.

The particular operational state which agent 110 is currently in reflects the current perceived threat level to the client. To ensure that malicious users cannot compromise agent 110, agent 110 has been designed to resist tampering and interference from unauthorized users, as shall be explained in more detail in the next section.

Securing the Bios Agent from Unauthorized Access

Embodiments of the invention protect resources, stored on a client, from theft and unauthorized access. Advantageously, the BIOS of each client in system 100 comprises BIOS agent 112. The BIOS is responsible for booting the client and starting the client system and its components, such as CPU and memory. The BIOS has two portions, a boot portion and a runtime portion. The boot portion of the BIOS is responsible for activities involved in booting the client, while the runtime portion of the BIOS is responsible for ongoing activities after the client has booted. In an embodiment, BIOS agent 112 communicates and interacts with the runtime portion of the BIOS.

By implementing BIOS agent 112 within the BIOS of each client of system 100, it is very hard for a party to circumvent, disable, or disengage the protection offered by embodiments of the invention. As shall be explained below, BIOS agent 112 is implemented in a manner that protects a party from circumventing, disabling, or disengaging BIOS agent 112. Further, BIOS agent 112 performs functions which protect resources of the client as well as the operating system agent 114.

It is important to secure BIOS agent 112 from tampering and interference from unauthorized users, as BIOS agent 112 stores policy data that describes the security policies which agent 110 follows. In an embodiment, the BIOS, and therefore BIOS agent 112, may be stored on a special microchip located on the motherboard of a client. The microchip is designed to ensure that the BIOS cannot be accessed by unauthorized parties. To achieve this goal, the microchip may be designed such that data stored on the microchip is (a) encrypted and (b) cannot be overwritten.

In an embodiment, BIOS agent 112 securely stores certain types of data in a manner that preserves the data through power cycles, disk re-formatting, software reinstallation, BIOS reflashing, and the like. For this purpose, BIOS agent 112 may maintain a small database, referred to as a Secure Data Memory (SDM), in the BIOS Flash Memory (EEPROM). Information stored in the SDM includes information about client provisioning from the manufacturing process, the BIOS agent 112 installation process, and the BIOS agent 112 registration process with server 120, including but not limited to a unique client identifier generated by server 120, password(s) for authentication and session keys, a server identifier, an application router domain name, information obtained from server 120 regarding how to encrypt or lock a hard-disk drive (HDD) of the client, and timeout limits. Additionally, the SDM may store information about the current operating state of BIOS agent 112, the status of recovery of the client, and/or information about the heartbeat message(s) communicated from operating system agent 114 to BIOS agent 112.

To maintain security, data in the SDM must be protected from intentional and unintended disclosure. BIOS agent 112 may encrypt data stored in the SDM which must not be disclosed. Similarly, none of the data stored in the SDM should be capable of being altered by a rogue software application. The BIOS Flash Memory meets these requirements, as it is a secure data storage area which may only be accessed and altered by authorized BIOS programs.

SDM may be implemented in a reserved area of Flash Memory and afforded the protection that it offers. Flash Memory is different from normal RAM memory in two significant ways. First, memory access is much slower. Second, there are a finite number of times that flash memory can be rewritten. To compensate, certain flash memory microchips have built-in means for “moving” data to different areas of memory. In an embodiment, BIOS agent 112 may further address the limit on the number of times flash memory may be rewritten by allocating multiple records, and when the limit is about to be reached in a first record, the contents of the first record are copied to a second record and the current-record pointer is updated to reference the second record.

In an embodiment, to ensure that BIOS agent 112 is implemented such that (a) BIOS agent 112 is prevented from being overwritten and/or deleted, and (b) BIOS agent 112 encrypts data to prevent unauthorized parties from reading the code and/or data that comprises BIOS agent 112, BIOS agent 112 may be implemented using an approach referred to as “SecurePhlash,” which is described in U.S. patent Ser. No. 11/026,813, entitled “Secure Firmware Update,” filed by Andrew Cottrell et al. on Dec. 28, 2004, the contents of which are herein incorporated by reference as if fully set forth herein. SecurePhlash may be used to ensure that BIOS agent 112 cannot be disabled without manually altering or changing the physical components of the client upon which BIOS agent 112 resides. SecurePhlash requires that a user provide not only the contents (i.e., bit patterns) to be reflashed, but the proper certificates of signature to ensure that the BIOS can only be reflashed by authorized parties. Passing this hurdle allows re-flashing to process in a system/chip mode that is only available to the BIOS, and thus, applications are unable to gain the necessary access to overwrite the contents of a portion of Flash Memory. SecurePhlash also provides the capability for excluding blocks of BIOS Flash Memory from being re-flashed, thereby providing a one-time only flash capability.

In another embodiment of the invention, the BIOS, and by extension BIOS agent 112, may be encrypted using a published specification called Trusted Platform Module (TPM) by Trusted Computing Group. Other embodiments of the invention may employ different approaches for encrypting data in the BIOS, as SecurePhlash, TPM, or other methods known to those skilled in the art may be employed.

As described above, BIOS agent 112 is implemented within the BIOS of each client of system 100, thereby making it very hard for a party to circumvent, disable, or disengage the protection offered by embodiments of the invention. The next section describes, at a high-level, how the protection offered by system 100 operates.

Protecting Resources of the Client

FIG. 4 is a flowchart illustrating the high-level functional steps of protecting resources of a client according to an embodiment of the invention. In step 410, operating system agent 114 intermittently sends a heartbeat message to BIOS agent 112. A heartbeat message is a communication that describes the operational state of operating system agent 114. As operating system agent 114 monitors resources of the client to detect any malicious or unauthorized activity, the operational state of operating system agent 114 reflects whether any resources of the client has been subjected to any unauthorized activity. The process of operating system agent 114 generating the heartbeat message is explained in further detail below in the section entitled “Examining Modules and Forming the Heartbeat Message.”

Thereafter, in step 420, BIOS agent 112 performs an action based on a policy. The one or more policies which BIOS agent 112 follows are described by data (denoted “policy data”) that is stored within the BIOS. A policy may specify that BIOS agent 112 is to perform a certain action in response to either (a) a particular operational state described by the heartbeat message, or (b) BIOS agent 112 not receiving the heartbeat message after an expected period of time. Additionally, as described in further detail below, other policies may instruct agent 110 to perform a certain action or command in response to the occurrence of other events or conditions.

As an example of the type of policy which BIOS agent 112 may follow, if the heartbeat message received by BIOS agent 112 indicates that a module of operating system agent 114 has been deleted, then the policy may interpret that as an indication of a malicious attack, and the policy may instruct BIOS agent 112 to perform one or more actions to address the malicious attack, such as disabling the client upon which BIOS agent 112 resides, emitting a loud sound to alert nearby persons that an unauthorized use of the client is occurring, and/or requiring the user of the client upon which BIOS agent 112 resides to resubmit authentication credentials to the client to continue use of the client. As another example of an illustrative policy which BIOS agent 112 may follow, if no heartbeat message is received by BIOS agent 112 after an expected period of time, then the policy may interpret that as an indication that operating system agent 114 has been compromised and is unable to send the heartbeat message, and the policy may instruct BIOS agent 112 to perform one or more actions to address the situation. Additional description of the nature of the policies of which BIOS agent 112 may follows is provided below in the section entitled “Security Policies.”

Having described the high-level functional steps of protecting resources of a client according to an embodiment of the invention, additional details about how operating system agent 114 monitors the resources of the client will now be presented.

Operating System Agent Operation

Operating system agent 114 may be responsible for, among other functions, monitoring the resources of the client upon which it is implemented, generating a heartbeat, and sending the heartbeat to BIOS agent 112. There are a variety of ways in which operating system agent 114 may be implemented. To provide a description about how operating system agent 114 may operate according to one embodiment of the invention, reference will be made to FIG. 5A, which is a block diagram 500 of the functional components of operating system agent 114 according to an illustrative embodiment of the invention. Note that in other embodiments of the invention, operating system agent 114 may comprise a different set of functional components, as certain functional components of operating system agent 114 depicted in FIG. 5A are optional or may be combined with one or more other functional components.

As shown in FIG. 5A, in an embodiment, operating system agent 114 comprises xSync module 502. xSync module 502 operates as a communications hub for operating system agent 114. xSync module 502 communicates with all of application modules 504, 506, and 508. xSync module 502 also handles all communications with server 120, the owner of the client, and the user of the client. xSync module 502 is also responsible for the installation and updating of the components of operating system agent 114. xSync module 502 may periodically check the status of application modules 504, 506, and 508, and subsequently generate a portion of the heartbeat message that reflects the status of application modules 504, 506, and 508.

In an embodiment, operating system agent 114 comprises or communicates with one or more application modules, such as application modules 504, 506, and 508. While three application modules are depicted in the embodiment shown by FIG. 5A, operating system agent 114 may comprise or communicate with any number of application modules. An application module performs a functional operation, such as a command and/or control operations sent from server 120 and received by operating system agent 114 or an action that is described by a policy.

Non-limiting, illustrative examples of the functions which a particular application module may perform include (a) encryption and backup services, (b) fetching the client's hardware and software configuration and identification information, (c) taking pictures or video with the client's webcam, (d) performing anti-theft functionality, such as disabling the client, emitting an alarm, and/or displaying a stolen alert screen, (e) deleting or removing files or resources stored on the client, (f) gathering forensic data, such as capturing the user's keystrokes, (g) retrieving files and/or resources from the client and bundling the files and/or resources (for example, by creating a .zip file) for xSync module 502 to upload to server 120 (possible via the FTP protocol), (h) preparing and registering components of operating system agent 114 (such as xSync module 502 or a particular application module) with server 120, and (i) detecting and fetching global positioning service (GPS) information.

chSync module 510 periodically forms a portion of the heartbeat message. chSync module 510 is also responsible for determining whether rpcSync module 512 is installed and uncorrupted, and if not, chSync module 510 is responsible for installing rpcSync module 512. The operation of chSync module 510 is explained in more detail below in the section entitled “Examining Modules and forming the Heartbeat Message.”

rpcSync module 512 starts executing at boot time and monitors for the presence of xSync module 502. If xSync module 502 is not running, then rpcSync module 512 will install and/or restore xSync module 502. rpcSync module 512 may form a portion of the heartbeat message based upon whether xSync module 502 is present and/or executing.

SafeAgent module 514 periodically forms the heartbeat message from the portions of the heartbeat message that are created by other components of operating system agent 114. After forming the heartbeat message, SafeAgent module 514 stores the heartbeat message in SMRAM, which is part of BIOS agent 112.

CryptOSD module 516 is the main interface for all components of operating system agent 114 with BIOS agent 112.

Note that the above discussion of the embodiment of operating system agent 114 depicted in FIG. 5A is merely illustrative of one embodiment. Other embodiments of the invention may implement operating system agent 114 differently. For example, other embodiments of the invention may implement modules or functions described herein as being performed by operating system agent 114 such that they are performed by BIOS agent 112, and vice-versa.

Additional details about how operating system agent 114 monitors the resources of the client upon which it is implemented, generates a heartbeat, and sends the heartbeat to BIOS agent 112 will now be presented.

Examining Modules and Forming the Heartbeat Message

The heartbeat message, generated by operating system agent 114 and communicated to BIOS agent 112, describes an operational state of operating system agent 114. As operating system agent 114 monitors the health of resources of the client, the operational state of operating system agent 114 is a reflection of the health of resources of the client. The content of the heartbeat message reflects whether normal operations of the client have been compromised or degraded. Agent 110 is a self-monitoring system which dynamically and continuously ensures that resources of the client are present and have not been subject to tampering and that agent 110 is operating correctly, and if not, agent 110 is able to repair or recover itself. The heartbeat message, as shall be explained in more detail below, informs BIOS agent 112 about the operational state of operating system agent 114. As a result, BIOS agent 112 may take an appropriate action, using one or more security policies, based upon the content of a heartbeat message or upon not receiving a heartbeat message after an expected duration of time (which suggests that operating system agent 114 is unable to send the heartbeat message to BIOS agent 112).

The heartbeat message comprises several parts that are derived independently of each other. Periodically, various modules (denoted “examining modules”) of operating system agent 114 examine the condition of other modules, and their associated files, of operating system agent 114 to determine if they are present as installed and operating as intended. This may be the only function performed by a particular examining module or the function may be performed in addition to other functions for which the examining module is also responsible. Each examining module of operating system agent 114 performs these checks for a subset of modules of operating system agent 114 and, for redundancy purposes, some modules of operating system agent 114 may be checked by more than one examining module. Furthermore, an examining module is treated like any other module of operating system agent 114, and therefore, may be examined by other examining modules of operating system agent 114. The number of examining modules in operating system agent 114 is a design decision based on the implementation of operating system agent 114. If there are too few examining modules in operating system agent 114, then it is potentially easier to defeat the protection provided by operating system agent 114; on the other hand, too many examining modules in operating system agent 114 may make implementation cumbersome.

A high-level approach for implementing examining modules according to an embodiment of the invention is depicted in illustration 600 of FIG. 6A. In the approach depicted by FIG. 6A, the BIOS checks an examining module, namely examining module 1, capable of restoring the entire operating system agent 114. In the embodiment depicted in FIG. 6A, operating system agent 114 consists of modules A-N. Examining module 1 is capable of restoring module A and examining module 2, which is capable of restoring modules A, B, and C-N.

A more specific example of implementing examining modules, based on the operating system agent shown by FIG. 5A, is illustrated by FIG. 6B. In the embodiment of FIG. 6B, the BIOS will check to see that chSync module 510 is operating correctly and all of its associated files are present and uncorrupted. If the BIOS determines that chSync module 510 does not pass this examination, then agent 110 enters recovery state 340. However, if the BIOS does determine that chSync module 510 passes this examination, then chSync module 510 checks the process and file status of rpcSync module 512 and xSync module 502 and records their status for SafeAgent module's 514 use in forming the heartbeat message. xSync module 502 also checks the process/file status of SafeAgent module 514, CryptOSD module 516, and all xSync applications modules 504, 506, and 508 and records their status for SafeAgent module's 514 use in forming the heartbeat message.

An examining module will check a number of other modules to ensure their processes and associated files are present and have not been corrupted. If a process is determined to be absent or corrupted, the examining module will re-establish it from its associated file if possible. If the associated file is absent or corrupted, a request will be made to server 120 to recover the appropriate file. The result of this examination, made by all examination modules, is summarized, saved, and becomes part of the heartbeat message. The details of the examination are recorded in a module status table (MST) which contains an entry for each examination module. SafeAgent module 514 assembles the heartbeat message using the information in the module status table and sends the heartbeat message to BIOS agent 112 for storage in the SMRAM.

Thus, the only way to circumvent the protection provided by agent 110 is to physically alter the client, because if portions of agent 110 are deleted or corrupted, they will be reinstalled or recovered by portions of agent 110 that reside in a portion of the BIOS which cannot be accessed except by authorized personnel.

The Content of the Heartbeat Message

A healthy client is a client that exhibits no signs or evidence of theft or unauthorized access. A healthy client has all of its appropriate processes executing in an uncorrupted manner as well as has all of its files (particularly its executable files, such as a file with an “.exe” extension) present and uncorrupted. An uncorrupted process or file is one that passes a security check, such as having a valid digital signature or a valid cyclic redundancy check (CRC). The heartbeat message generated by operating system agent 114 may identify the “health” of the client upon which operating system agent 114 resides.

A heartbeat message may be implemented in a variety of different ways. According to one embodiment, the heartbeat message contains information that identifies, for a particular module or component of operating system agent 114, whether the module or component is present and uncorrupted. Such an embodiment may indicate whether a particular module or component of operating system agent 114 is executing and is uncorrupted as well as indicating whether all files associated with the module or component are present and uncorrupted.

According to another embodiment, additional information that describes the nature of the potential security threat(s) may be contained in the heartbeat message. For example, if a particular module of operating system agent 114 is moved or deleted every five minutes, then this additional information may be contained within the heartbeat message. Such additional information may provide additional insight into potential security threats, and may be referenced by a security policy. For example, a particular security policy may be established that states that if the same file or resources is deleted three times in a particular time period (which is suggestive of a malicious attack on the client), then agent 110 should enter the disable state 330.

If the heartbeat identifies any evidence of theft or unauthorized access, then when BIOS agent 112 receives the heartbeat, BIOS agent 112 follows security policies stored by BIOS agent 112 to address the potential theft or unauthorized access. The security policies followed by BIOS agent 112 may strike a balance between maintaining the integrity of agent 110 (and by extension the resources of the client upon which it resides) and the convenience of the user of the client, as locking the client due to the accidental deletion of a file could be a major inconvenience for the user

In an embodiment, if a process or file is removed, then agent 110 will follow security policies stored by BIOS agent 112 to determine how to address the situation. For example, a particular security policy may instruct agent 110 to enter recovery state 340 if a process or file is removed or corrupted. In recovery state 340, agent 110 may attempt to communicate with server 120 to restore the particular process or file that has been removed. For example, server 120 may be able to provide agent 110 with a new version of the process or file that has been corrupted or removed. If the missing resources is a low priority resource, and a connection to server 120 cannot be established by agent 110, a security policy may instruct agent 110 to continue and to defer recovery of the missing resource; however, care should be given to defining security policies, as when a process and its corresponding executable file are missing, it is unlikely to be accidental.

While agent 110 is in recovery state 340, agent 110 monitors resources of the client for further degradation. Any further degradation of resources of the client is most likely an indication of malicious intent, as a consequence, further degradation of resources of the client may be addressed by the security policies stored by BIOS agent 112 and established by the owner of the client. For example, according to an exemplary security policy, if agent 110 determines that resources of a client have continued to degrade while agent 110 is in recovery state 340, then agent 110 may enter disable state 330. Although the behavior of agent 110 when agent 110 is in disable state 330 may differ according to the particular security policies stored by agent 110, a typical behavior of agent 110 when agent 110 is in disable state 330 is to “lock” the client by preventing anyone to access the client without providing two or more levels of authentication to “unlock” the client.

Additional details will now be provided about the operation of BIOS agent 112.

Bios Agent Operation

FIG. 5B is a block diagram of the functional components of BIOS agent 112 according to an embodiment of the invention. BIOS agent 112 receives the heartbeat message from operating system agent 114 and stores security policies which agent 110 receives from server 120. Additionally, BIOS agent 112 performs one or more actions in accordance to the security policies. For example, BIOS agent 112 may perform an action, dictated by a security policy, in response to either (a) the contents of a received heartbeat message, or (b) BIOS agent 112 not receiving the heartbeat message after an expected period of time.

BIOS agent 112 may be implemented in a variety of different ways. To illustrate how BIOS agent 112 may be implemented according to an embodiment of the invention, consider FIG. 5B, which is a block diagram of BIOS agent 112 according to an embodiment of the invention. As illustrated by FIG. 5B, in an embodiment BIOS agent 112 includes FSR™ module 550. FSR™ module 550 serves as the primary interface for modules of operating system agent 114 to communicate with BIOS agent 112. FSR™ module 550 evaluates all communications received from modules of operating system agent 114 to ensure that the communications originate from a valid module of operating system agent 114 as well as routes valid communications, from modules of operating system agent 114, to their appropriate destination within BIOS agent 112.

Strong ROM 552 provides security services for the BIOS of the client upon which it resides. In particular, strong ROM 552 may be used to provide encryption/decryption functionality as well as authentication functionality. Strong ROM 552 may be implemented as a binary module which executes in system management mode (SMM) inside SMRAM. Strong ROM 552 provides authentication and cryptographic services, including authentication of binary modules and caller validation for applications that access firmware services. Strong ROM 552 is an illustrative example of BIOS security services, but it is contemplated that other security services may be used by other embodiments of the invention. For example, a client may be implemented with other approaches for performing encryption/decryption and/or authentication.

NTFS Driver 554 is a module that is responsible for copying chSync module 510 and other associated files to the operating system.

TCO 556 is a timer which is used to determine when BIOS agent 112 will examine the recent heartbeat message received from operating system agent 114.

Heartbeat handler 558 is responsible for examining the heartbeat message received from operating system agent 114. Heartbeat handler 558 may either reset the heartbeat message or take remedial action depending on the nature of the changes in the heartbeat message.

State change processor (SCP) 560 is a module which examines the changes in the heartbeat message received from operating system agent 114, the current state of agent 110, and takes appropriate action depending on the security policies established by the owner of the client.

As BIOS agent 112 acts upon policies and instruction received from server 120, additional detail will now be provided about how a client and server 120 may interact.

Interactions Between Clients and the Server

FIG. 7 is a flowchart illustrating the functional steps of communicating a policy from server 120 to a client according to an embodiment of the invention. The steps of FIG. 7 may be used to ensure that agent 110, residing on a client, possesses the latest security policies issued by the owner of the client. Additionally, the steps of FIG. 7 also ensure that a party external to each client in system 100, namely sever 120, maintains accurate information about the status of each client so that the owners of each client may be apprised. For purposes of providing a clear explanation, the steps of FIG. 7 shall be explained below with reference to agent 110 executing on client 106.

In step 710, upon client 106 undergoing a change in operational state, operating system agent 114, executing on client 106, sends a state message to server 120. The state message describes a new operational state of client 106. Clients in system 100 periodically contact server 120 whenever the client undergoes a change that may affect its operation or present a change in the risk of theft or unauthorized access of the client. Non-limiting, illustrative changes which may result in client 106 sending a state message to server 120 include a change in the IP address of client 106, a change to the hardware configuration of client 106, a change to the software configuration of client 106, a toggling of the power supplied to client 106, a change to a configuration setting of client 106, a change in the physical location of client 106 (such as information from a global position service (GPS) indicating that client 106 has moved outside of a bounded geographical region), and a change in the heartbeat message received by BIOS agent 112 from operating system agent 114.

Server 120 stores the information contained in the state message. Server 120 also examines any policies that affect client 106 to determine what, if any, action(s) should be performed by server 120 in response to receiving the state message from client 106. An applicable policy may result in a command being sent from server 120 to client 106 that affects the mode of operation of client 106, such as disabling some function of client 106 (for example, the USB ports of client 106). In more serious situations, server 120 may instruct agent 110 executing on client 106 to change its state to disable state 330, and force client 106 to reset, reboot, and enter a mode that requires multi-level user authentication.

Server 120 may periodically determine if there are any pending policy changes to send to a client, and if so, send a policy message containing the new policies to the client. In an embodiment, server 120 may determine if there are any pending policy changes to send to client 106 in response to receiving a state message from client 106.

In step 720, client 106 receives a policy message from server 120. The policy message is a communication, sent over communications link 130, which contains policy data which identifies one or more security policies which client 106 is to follow. In an embodiment, the owner of client 106 may establish the security policies using web interface 210 of server 120.

In step 730, agent 110 of client 106 stores the policy data, received from server 120, in the BIOS of the device. As a result, the security policies which client 106 is to follow are stored in a secure location which is protected from unauthorized access.

It is noted that while step 730 is typically performed after the performance of step 720, step 710 may be performed at any time relative to steps 720 and 730. Thus, the steps of FIG. 7 may be performed in different orders than that depicted, as step 710 may be performed in parallel to, or after, the steps of 720 and 730.

Clients May Follow Security Policies without the Aid of the Server

Client 106 is not dependent on server 120 for protecting the client's data from theft and/or unauthorized access. Without being connected to server 120, client 106 is able to determine its state, changes to its state, and according to the policies established by the owner, react to those changes, which may include entering a disable state which requires multi-level authentication before the client can re-boot and resume operations.

FIG. 8 is a flowchart illustrating the functional steps of securing a device according to an embodiment of the invention. By performing the steps illustrated by FIG. 8, a client may protect its resources from theft and/or unauthorized access by following security policies stored in the BIOS of the client. For ease of explanation, the steps of FIG. 8 shall be described below with reference to client 106.

In step 810, client 106 stores policy data within the BIOS of client 106. The policy data describes one or more security policies which client 106 should follow. Client 106 may receive the policy data in a policy message from server 120 as described above with reference to step 720.

In step 820, upon operating system agent 114 of client 106 detecting that a certain condition, specified by a particular security policy, has been met, BIOS agent 112 of client 106 performs one or more actions specified by the particular security policy. Advantageously, if a malicious user steals client 106 or accesses client 106 in an unauthorized manner, agent 110 may protect resources of client 106 without any assistance or communication from server 120. For example, the security policies stored in the BIOS of client 106 may indicate that, upon detecting signs that client 106 has been stolen, agent 110 should turn client 106 “into a brick,” that is to say, prevent client 106 from being able to boot, thereby rendering client 106 inoperable but protecting the data stored thereon from unintended disclosure to a malicious party.

Security policies are discussed in greater detail below in the section entitled “Security Policies.” Additional information about the types of actions that a client may perform is presented below in the section entitled “Illustrative Commands that a Client may Perform.” Also, discussion about the types of conditions that a security policy may reference is presented below in the section entitled “Illustrative Conditions that may be Referenced by a Security Policy.”

Security Policies

A security policy, as used herein, refers to a policy which a client of system 100 may follow to protect the resources of the client from theft and/or unauthorized access. A client in system 100 may follow any number of security policies. The security policies which a client of system 100 follows are stored in the BIOS of the client.

A security policy may initially be defined using web interface 210 of server 120. For example, the owner of a client (which may correspond to a company and may be, but need not be, different than the intended user of a client) may use a web browser to define one or more security policies, and may submit the defined one or more security policies to server 120 via web interface 210.

In an embodiment, a security policy specifies that one or more actions are to be performed by a client if one or more conditions are met. A condition referenced by a security policy serves to indicate when a particular action is performed. As such, a condition referenced by a security policy may reference any quantum of evidence that, when present, would motivate one to perform the action specified by the policy. Illustrative examples and further discussion about the types of conditions that a security policy may reference is presented below in the section entitled “Illustrative Conditions that may be Referenced by a Security Policy.”

In an embodiment, a security policy may be performed in a “1-click” fashion. That is to say, the owner of one or more clients may use web interface 210 of server 120 to, with the click of one mouse button or keystroke, instruct server 120 to either send one or more predefined policies to one or more clients of the owner or send one or more predefined commands to one or more clients of the owner. For example, the owner of a plurality of clients may use web interface 210 to organize the plurality of clients into one or more logical groupings, such as by division, department, or type of client. Such logical groupings may aid the owner of the plurality of clients in managing the security policies followed by a large number of clients. After the owner has defined a set of one or more commands and/or a set of one or more security policies, the owner may disseminate the set of one or more commands and/or the set of one or more security policies to a logical grouping of clients by sending a single instruction (a “1-click”) to web interface 210 of server 120.

Using embodiments of the invention, a corporate IT department may manage the security policies of any number of clients. The IT department may establish different security policies for clients used by personnel in the engineering department than clients used by personnel in the sales department. For example, the IT department may establish a policy, only to be used by clients operated by personnel in the sales department that will erase the hard-drives of stolen clients that are used by sales personnel under the rationale that the data stored on a client used by someone in the sales department may be very sensitive, but easy to recreate. On the other hand, the IT department may establish another policy, only to be used by clients operated by personnel in the engineering department, that will encrypt the data stored on the hard-drives of stolen clients operated by engineering personnel under the rationale that the data stored on a client used by someone in the engineering department may be hard to recreate. In this way, a centralized entity (such as an IT department) may establish a different set of security policies for various groups of clients, and the centralized entity may instruct server 120 to implement security policies or send commands to each client in a group of clients by issuing a single instruction to server 120.

In an embodiment of the invention, the owner of a client (such as a company) may communicate with server 120 to send commands or policy data to one or more clients owned by the owner; however, the user of a client may not modify the policy data stored on the client. In this way, a company or other centralized entity that manages a large number of clients may ensure that each client is implementing the appropriate security policies. The user of a client cannot configure the client in a manner that disables or otherwise reduces the security protection afforded by the securities policies stored by BIOS agent 112 on the client.

Illustrative Commands that a Client May Perform

In an embodiment, server 120 may issue a command to a particular client for immediate performance. Additionally, a client may store a security policy which instructs the client to perform a particular command when a particular condition is met. Embodiments of the invention may implement a variety of different commands, such as retrieve, erase, encrypt, and disable. Each of these commands shall be explained in more detail below.

The retrieve command instructs a client to retrieve a particular resource, such as a file, and send a copy of the resource to server 120 over communications link 130. The retrieve command is useful when the owner of a missing or stolen client would like to retrieve a limited number of resources from the lost or stolen client. In an embodiment, resources that are retrieved using the retrieve command are then deleted from the missing client, as the client may be in possession of a malicious user.

In an embodiment, to issue a retrieve command to a client, the name of the resource (which may be a file or folder, for example) is included as an argument to the retrieve command. In another embodiment, the name of the resource to be retrieved and the path to the resource is included an argument to the retrieve command.

There may be limitations to the size of resources that are able to be retrieved using the retrieve command, as it would not be desirable to inundate server 120 with a large volume of incoming data.

The erase command instructs a client to erase one or more resources, such as a file. The erase command is use to erase sensitive or confidential data from a client. In many cases, data stored on a client may be backed-up or stored in another location on a regular basis; consequently, the real concern when a client is stolen may be that sensitive or confidential data could be accessed by a malicious party, rather than a concern that the client itself may not be retrieved. Thus, the erase command may be used to affirmatively erase data stored on client, thereby preventing the data from being accessed by unauthorized parties. In an embodiment, the path to the resources that are intended to be erased and well as information identifying the resources to be erased should be identified as arguments to the erase command.

In an embodiment, when a client performs the erase command, if the client is able, the client sends a confirmation, to server 120, that the data identified by the erase command was erased. In this way, the owner of the client may have some assurance that sensitive or confidential data on the client was not accessed by a malicious party.

The disable command instructs a client to shut down and become unable to boot. Thus, a client that has been disabled by performing the disable command is unable to reboot. For this reason, a client may be said to “turn into brick” by via the disable command, because the client, after performing the disable command, is unable to operate, and becomes “as useful as a brick” to an unauthorized user.

In an embodiment, a client that has been disabled by performing the disable command may be able to return to operational status if one or more authentication credentials are provided to the client. Presumably, a thief who stole a client would not know the proper authentication credential(s) to submit to the client to return the client to an operational state. In such an embodiment, it may be necessary to obtain an authentication credential from two or more parties, such as the current user of the client and the owner of the client. The user of the client may be prompted to submit an authentication credential to the client if a blank screen or a screen displaying a warning is shown by the client. The client would not necessarily have to be powered down, but instead, would not respond to any input to the client (such as mouse movements or keystrokes) except for a secret sequence of input (such as holding two or more keys together at the same time). If a user is unfamiliar with this procedure, then the user will likely believe the client is broken, and may not attempt any further action to retrieve data from the client. However, if the user is familiar with this procedure, the user may quickly submit the secret sequence of input to the client to enable the user to gain access to the client.

In an embodiment, when a client is disabled by performing the disable command, the client may emit a loud alarm. Such an approach may be useful for notifying nearby people the client may be stolen and discouraging continued access of the client by the malicious party. In an embodiment, when a client is disabled by performing the disable command, the client may display a message on a screen indicating the client has been stolen or is being accessed in an authorized manner. The message may also contain information to assist in unlocking the client. For example, the message may instruct the user of the client call a particular telephone number to unlock the client. When the user calls the telephone number, the user's identity may be confirmed, and the user may be given a password or other authentication credential to provide to the client to unlock the client.

The specific actions taken by a client that has been instructed to perform a disable command may be defined either by the disable command itself or by a security policy stored by the client. For example, the client may store policy data that describes a policy that indicates that, when the client receives a disable command, the client is only to emit an alarm if the physical location of the client is outside of a particular geographical area.

Other illustrative commands which may be referenced by a policy or be conveyed to a client from a server include an instruction to record the keystrokes of the user of the client and an instruction to take one or more pictures or video using a web cam or other digital camera associated with the client.

The commands discussed above may be sent from server 120 to a particular client for immediate execution by the client. Alternately, as discussed below, the commands may be referenced by policy data, which defines one or more security policies, sent from server 120 to a particular client. When a condition referenced by a policy is met, then a command referenced by a policy may be performed. For example, server 120 may send a command to client 104 to enter disable state 330. Alternately, server 120 may send policy data to client 104 which contains a policy that states the client should enter disable state 330 when a condition is met by the client, such as the client's IP address changing or the client physically moving outside of a bounded geographical area identified by the policy.

Illustrative Conditions that May be Referenced by a Security Policy

In an embodiment, a security policy specifies that one or more actions are to be performed by a client if one or more conditions are met. A condition referenced by a security policy serves to indicate when a particular action is performed. Security policies may reference a wide variety of conditions. Non-limiting, illustrative examples of conditions which may be referenced by a security policy, as an indication of when a particular action is to be performed, includes: (a) when an IP address of the client changes, (b) when the name of the client changes, (c) when the client does not connect to server 120 for a predefined length of time, (d) when the client does not receive a heartbeat message from the operating system agent executing thereon after an expected period of time, and (e) when the user of the client is not able to supply valid authentication credentials.

In an embodiment, a security policy may specify that the client may reboot a certain number of times without receiving a heartbeat message from the operating system agent residing on the client. While allowing a client to reboot without receiving a heartbeat message may introduce an element of risk to the resources of the client, it may be necessary to reboot the client without receiving a heartbeat message when the client is being repaired. As a result, a security policy that specifies, as a condition to the perform of a security action, number of times the client may reboot without receiving a heartbeat message from the operating system agent residing on the client should balance convenience versus security.

Two other conditions that may be referenced by securities policies of embodiments of the invention involve geofencing and the proximity of the client to a wireless device. Each of these techniques is described in greater detail below.

Geofencing

In an embodiment, a client of system 100 may be designed to perform an action or command whenever the client physically moves outside of one or more bounded geographical areas. An owner of a client may define one or more bounded geographical areas using web interface 210 of server 120. The owner may then define one or more policies that instruct a client to perform an action or command whenever the client physically moves outside of, or into, one or more bounded geographical areas. The defined policies, which reference the one or more bounded areas, may be communicated from server 120 to one or more clients.

A client storing a security policy that references one or more bounded geographical areas may employ an application module, of operating system agent 114, to detect and fetch global positioning service (GPS) information for the client. Thus, if the client physically moves outside of the one or more bounded geographical areas referenced by the security policy, the client may be apprised and perform the one or more actions specified by the security policy.

To illustrate an example, a security policy may be stored on a client that instructs the client to enter a disabled state if the client is physically moved outside of one or more bounded geographical areas. As another example, another security policy may be stored on the client that instructs the client to perform a different action, such as erasing all data stored on the client, if the client is physically moved into one or more bounded geographical areas, such as a bounded geographical area corresponding to a country that has weak intellectual property laws or to a location associated with a competitor.

There is no limit to the size, shape, or number of bounded geographical areas which may be referenced by a security policy. For example, a security policy may define a bounded geographical region around a particular building or physical property of the owner of the client. In this way, if the client is taken outside of a building or off the property of the owner, the client may perform a certain action, such as disabling itself or erasing sensitive or confidential information.

Proximity to Wireless Device

In an embodiment, a client of system 100 may be designed to perform an action or command whenever the user of the client moves his or her mobile device (such as a cell phone) beyond a specified distance from the client. For example, client 106 may immediately lock and/or power down and possibly enter a sleep mode or hibernation mode when the user of client 106 walks with his cell phone further than a specified distance from client 106. Correspondingly, when the user of client 106 moves his cell phone within the specified distance to client 106, client 106 may unlock and/or power on client 106 and/or exit the sleep/hibernation mode. This approach advantageously allows a client to become secure and/or save power whenever the user walks away, with a mobile device, from the client.

FIG. 9 is an illustration of a proximity condition according to an embodiment of the invention. As shown by FIG. 9, a zone of use is established around the client. If the user of the client leaves the zone of use with a mobile device, such as a Bluetooth cell phone, a security policy, stored by the client, may instruct the client to perform a certain action or command. The distance between the user's mobile device and the client is determined by evaluating the strength of the Bluetooth signal between the user's mobile device and the client.

Additional details about the approach depicted in FIG. 9 may be found in U.S. patent Ser. No. 12/321,504, entitled “Secure Platform Management with Power Savings Capability,” filed by Gaurav Banga et al. on Jan. 21, 2009, the contents of which are herein incorporated by reference as if fully set forth herein.

Facilitating the Legitmate Use of Clients

Embodiments of the invention not only prevent the theft and unauthorized access of resources of a client, but also accommodate the legitimate use of clients by authorized users. An authorized user may have a legitimate need to remove a hard-disk drive or other persistent storage medium from a client and install a new hard-disk drive or other persistent storage medium in the client. The new hard-disk drive or persistent storage medium would not have operating system agent 114 installed, whereas the client would have BIOS agent 112 installed in the BIOS of the client. As the new hard-disk drive or persistent storage medium does not have operating system agent 114 installed, BIOS agent 112 on the client would not receive a heartbeat. In response to not receiving a heartbeat after an expected period of time, BIOS agent 112 checks to see if modules of operating system agent 114 are installed and uncorrupted; consequently, BIOS agent 112 would soon discover that operating system agent 114 is not installed in the new hard-disk drive or persistent storage medium. Thereafter, BIOS agent 112 copies chSync module 510 to the operating system of the client and communicates with server 120 to obtain data necessary to install operating system agent 114 in the operating system of the client. In this process, BIOS agent 112 sends information identifying the client to server 120, such as the serial number of the client. In this way, BIOS agent 112 may cause operating system agent 114 to be installed upon the new hard-disk drive or persistent storage medium and may repopulate operating system agent 114 with all the appropriate modules using the data obtained from server 120.

If a hard-disk drive (HDD) storing operating system agent 114 is removed from an old client and installed in a new client that does not have BIOS agent 112 stored thereon, and the new client is powered on, operating system agent 114 would try to send a state message to server 120. Working in conjunction with server 120, operating system agent 114 would attempt to repopulate BIOS agent 112 in the BIOS of the new client. The user of the new client may be asked by operating system agent 114 if the user would like to transfer a license to agent 110 from the old client to the new client. The owner of the old client may receive an email from server 120 notifying the owner about the request to transfer the license from the old client to the new client. The owner of the old client would need to approve of the transfer of license from the old client to the new client before data may be accessed from the hard-disk drive (HDD) using the new client. In an embodiment, each agent 110 requires a license to operate, and if either BIOS agent 112 or operating system agent 114 resides on a client for which it does not have a license, it will not operate. To uninstall agent 110 from a client, one needs to submit an appropriate authentication credential to do so.

Composite Tracking Algorithm (CTA)

In an embodiment, a server may employ a composite tracking algorithm (“CTA”) which considers different types of location information for purposes of determining the present location of a client. There may be a variety of different types of location information sent by a client to server 120 which may be used by server 120 to identify the physical location of the client. Such different types of location information may include IP trace information, global positioning system (GPS) information, and triangulation information based on one or more Wi-Fi access points. These different types of location information and how they can be used by embodiments shall be discussed below.

IP trace information may include the public IP address of the client and the set of IP addresses that data packets sent from the client pass through to reach server 120. The public IP address of the client may be determined by gathering the source IP address from the server socket receiving the client connection. The list of hops through which the data packets sent from the client go through may be determined by sending adaptive TTL (time to live) UDP packets to server 120 from the client. In order to determine if the client is being an IP proxy, server 120 may correlate the list of hops with the public IP address of the client. In this way, server 120 may effectively discover the real public IP address of the client. The real public IP address of the client is then matched against a database of Internet Service Providers (ISPs) which returns the probable address of the originating client message. This probable address of the originating client message may then be translated to a set of longitude and latitude coordinates.

Global positioning system (GPS) information comprises coordinates, namely longitude and latitudes, gathered by a GPS service available to the client as well as other information provided by the GPS service, such as accuracy information.

It is noted that certain clients may not have access to a GPS service (for example, they may lack hardware necessary to support such a service); consequently, such GPS information may not be available for all clients. Also, it is observed that certain GPS services do not operate in certain locations, such as indoors. Thus, even if a client does have the necessary hardware and software to support a GPS service, occasionally GPS information from the GPS service may not be available to a particular client.

Triangulation information for a client may include a list of public Wi-Fi access points surrounding the client as well as the signal strength of each Wi-Fi access point accessible by the client. The list of surrounding Wi-Fi access points, and their signal strength, may be formatted and correlated with a database of public Wi-Fi access points by server 120 to determine a probable set of longitude and latitude coordinates for the client. Note that the database of public Wi-Fi access points employed by server 120 may be updated over time to reflect new information about available Wi-Fi access points.

While each of these different types of data may be used by server 120 to identify a current location for a client, certain types of data may be more accurate or reliable than others. It is observed that GPS information is more accurate and indicative of the correct physical location of a client; however, as explained above, GPS information for a particular client may not always be available. Triangulation information, while not as accurate and reliable in identifying the correct physical location of a client as GPS information, is more accurate and reliable than IP trace information. However, triangulation information also may not always be available, e.g., the client may not be able to detect any nearby recognizable Wi-Fi access points. Additionally, while IP trace information is less accurate than either GPS information or triangulation information in determining the correct location of a client, it is always obtainable if the client can communicate to server 120 over communications link 130.

In an embodiment, a client may intermittently send location information to server 120. For example, as location information may be sent from a client to server 120 in a state message, location information may be sent from a client to server 120 anytime the client normally sends to server 120 a state message as discussed above. Additionally, a client may store policy data that defines one or more security policies which instruct the client when to send, to server 120, a certain type of location information.

FIG. 10A is a graph 1000 that illustrates server 120 receiving, from a client, location information, such as GPS information, triangulation information, and IP trace information, over time according to an embodiment of the invention. The x-axis of graph 1000 corresponds to time and the y-axis of graph 1000 corresponds to the perceived accuracy or reliability of the received location information. Points in time t₁, t₂, t₃, and t₄, which are identified on the x-axis, refer to points in time that demarcate time slices of length n, where n is a configurable amount of time. For example, n may be one hour. Server 120 may configure location information received from a client for a certain amount of time. While FIG. 10 depicts four prior points in time, server 120 may receive location information over any length of time and may consider any received location information for a configurable amount of time.

Between two different points in time, a variety of different types of location information may be received by server 120. For example, between t₁ and the current time, one instance of IP trace information is received by client 108. However, between t₂ and t₁, two instances of triangulation information, one instance of IP trace information, and no instances of GPS information are received by server 120.

In an embodiment, the client may be configured to send any type of location information, to server 120, which it is able to send. In other embodiments of the invention, the client may be configured to send, to server 120, only the type of location information deemed most accurate, e.g., the client may not send triangulation information to server 120 if it is able to send GPS information to server 120. As shall be explained in more detail below, server 120 may consider multiple factors in determining how to interpret any received location information.

Using Location Information at the Server

FIG. 10B is a flowchart 1050 illustrating the steps of protecting a client using location information according to an embodiment of the invention. In step 1062, server 120 intermittently receives location information from a client. Such location information may comprise global positioning service (GPS) information for the client, triangulation information, for the client, based on one or more Wi-Fi access points, and/or IP trace information for the client. Location information may also include any other type of data which may be used to identify, at any level of granularity, where a client is or may be located.

In step 1064, a software component, executing on server 120, determines the present location of a particular client. The software component of step 1064 may be implemented by, or correspond to, runtime processing component 220 of server 120 using the CTA to determine the present location of the client for which location information was received in step 1062. Step 1064 may be performed using a variety of different approaches. According to one approach, runtime processing component 220 determines whether any portion of GPS information, triangulation information, and IP trace information has been received by server 120 during an interval of time (denoted the “period of interest”) measured from the current time. The exact length of the period of interest may vary from implementation to implementation and is configurable. For example, if n is equal to one hour, then the period of interest may be six hour, eight hours, or twenty four hours in various embodiments. In other embodiments, the period of interest may be less than n, e.g., the period of interest may be thirty minutes while n is equal to one hour. The length of time of the period of interest may be selected to maximize the probability of obtaining reliable location data, e.g., by balancing the likelihood of receiving GPS information (which weighs in favor of a longer period of interest) with the need to consider timely location information (which weighs in favor of a shorter period of interest).

Runtime processing component 220 may order different types of location information in a sequence based on accuracy, and thereafter use the sequence of different types of location information when examining the types of location information received during the period of interest in determining the current location of the client. To illustrate, if any GPS information was received during the period of interest, then runtime processing component 220 may determine the present location of the client using the most recent GPS information that was received during the period of interest. If triangulation information, but no GPS information, was received during the period of interest, then runtime processing component 220 may determine the present location of the client using the most recent triangulation information that was received during the period of interest. When no GPS information or triangulation information is received during the period of interest, then runtime processing component 220 may determine the present location of the client using the most recent IP trace information received during the period of interest.

Another factor to consider is whether it would be advantageous to use more reliable location information received prior to less reliable location information. For example, between the current time and t₁ depicted in FIG. 10A, only IP trace information is available. However, IP trace information is not as reliable as triangulation information. Thus, it may be desirable to consider expanding the period of interest to at least t₂ so that triangulation information for the client may be considered, even though it is older than the IP trace information received after t₁.

According to another approach, step 1064 may be performed by runtime processing component 220 determining a weight to be associated with any portion of the GPS information, the triangulation information, and the IP trace information that was received during the period of interest. Each type of location information may have, but need not have, a different weighted value in the composite tracking algorithm (CTA). For example, in an embodiment, GPS information may have the highest weight in the CTA when the client is in a position to gather relevant and accurate longitude and latitude coordinates from its GPS service. IP trace information may have the lowest weight and Wi-Fi triangulation may have an average weight. Runtime processing component 220 may subsequently calculate the present location of the client by determining a weighted arithmetic mean for the portions of GPS information, the triangulation information, and the IP trace information that were received during the period of interest.

Embodiments of the invention may assign any weight to a particular type of location information. In an embodiment, the weight associated with a particular type of location instance, or a particular instance of location information, may be updated or adjusted to reflect the accuracy associated therewith. For example, if GPS information is perceived as being more reliable than IP trace information, then GPS information may be assigned a greater weight than IP trace information. Alternately, if a particular instance of location information (regardless of type) is suspicious or suggestive of being incorrect, then the weight associated with the particular instance of location information may be reduced.

In step 1066, in response to server 120 following a security policy that is described by policy data stored by server 120, server 120 performs an action, specified by the security policy, based on the present location of the client. As described above, a security policy may instruct server 120 to take a wide variety of actions in response to the present location of a client. For example, if a client is outside of a particular bounded geographical area (for example, the area in which the client is expected to be used), then server 120 may instruct the client to take certain heightened security procedures. As another example, if the present position of a client corresponds to a public place, such as a coffee shop, then server 120 may instruct the client to perform another set of security procedures, such as disabling the client if the cell phone of the user assigned to the client is not within a specified distance of the client.

In an embodiment, webcam digital picture and/or video data (hereafter “webcam shot data”) may visually depict the operator of the client. Webcam shots (pictures or video) may be taken at boot time, on demand, and/or at periodic intervals, and sent to server 120, where the webcam shots are associated with the geographical location of the client at the time the shot was taken. Webcam shot data may include one or more digital pictures, digital video, or both. Webcam shot data may be useful in viewing the operator of the client at a particular location. For example, if a client is stolen, webcam shot data may be used to obtain a picture of the operator of the stolen client, which is likely the person responsible for the theft of the client.

In an embodiment, server 120 may generate display data which, when rendered, depicts an interface which shows the current location of a client on a map. The map may be displayed on a web page that is accessible by the owner of the client. The map may depict a number of most recent geographical locations on the map for which webcam shot data for the client is available. The webcam shot data may be displayed on the map corresponding to the location at which the webcam shot data was taken by the client. In this way, server 120 may use the webcam shot data to visually display a picture or video of the operator of the client at different locations on the map.

In an embodiment, which shall be explained in further detail below, information about the current location of the client may be periodically transmitted from server 120 to a client so that the client can be apprised of its current location.

Location Aware Client

In an embodiment, a client may operate in a normal mode and an alert mode. By default, a client is in normal mode. However, if the security policies of the client indicate that certain conditions are satisfied, then the client may enter alert mode. When the client is in alert mode, the client may perform one or more actions to protect itself. The severity of the actions may be based on the amount of danger or risk the client perceives itself to be in.

In an embodiment, a client may consider a variety of factors in determining whether to enter alert mode. For example, in considering whether to enter alert mode, the client may consider (a) whether the client is able to detect a known network access point, regardless of whether of client is able to access the known network access point, (b) the operating system access point classification (public, private, workplace, etc.), (c) proximity to a cell phone or other wireless device, (d) access or proximity to certain network equipment (e.g., a router, domain name server, server, etc.), and (e) information available from a GPS service provided by the client.

In an embodiment, when a client enters alert mode, the client may contact server 120 to determine whether there are any pending messages for the client and to inform server 120 that the client is in alert mode. Also, after entering alert mode, the client may attempt to establish a persistent connection with server 120, so that any request from server 120 is immediately executed by the client. Performing requests in real-time is also discussed below in the section entitled “Instant Command.”

A security policy may instruct the client to perform any type of action when the client enters alert mode. Such actions that a client may take in response to a security policy when the client enters alert mode include, without limitation, logging out of the operating system and requiring the user to submit a valid password, prompting for an unlock key when resuming from hibernation, disabling the client, degrading the client, and increasing the frequency of the reports the client makes to server 120. For example, a client may recognize that it is in an area that is unknown (e.g. a coffee shop) versus a known area (such as the home of the user or at the office), and modify its behavior accordingly. The client may determine what action to take based on information identifying the client's current location and/or other current information that describes its geographical location (such as which computer networks the client may access) and the security polices stored on the client by BIOS agent 112. As an example, a client may enter degraded state 320 if the client detects that the client is in an unknown network. Advantageously, embodiments of the invention enable the client to raise its level of security automatically based on its current geographical location and its surroundings.

Instant Command

In an embodiment, commands may be sent by server 120 to a particular client for execution in real-time. Thus, if a user wishes a particular client to immediately perform a particular command, the user may access an interface provided by server 120 to issue a command, for immediate execution, to a particular client. In order for a client to be instructed, in real time, to perform certain commands or special tasks (such as to disable, to retrieve a file, to erase one or more files) that are initiated using a user interface provided by server 120, a communication channel is kept open between the client and server 120 at all times when there is network connectivity. This communication channel enables server 120 to initiate a connection to the client on demand, which cannot be accomplished in a natural way in today's network environments with network address translation and firewalls.

The communication channel effectively enables a command to be sent from server 120 to the client for immediate execution upon receipt. For example, a user that wishes to disable his lost laptop may access the user interface provided by server 120, and initiate an instant lock command on his lost laptop, which would effectively disable his laptop in real time. Likewise, the user could initiate other commands to be performed on his laptop immediately upon receipt, such as a retrieve command or an erase command.

BCOI (BIOS Connect Over Internet)

In an embodiment, agent 110 of a client may include a component (referred to as BCOI Failsafe BIOS component) which is configured to directly communicate with server 120 from the BIOS level of the client using the network stack. This transport mechanism is configured to allow (a) obtaining policy updates and/or commands on the BIOS level directly from server 120, (b) download and update modules of agent 110, such as those modules required for persistency, (c) support one-time password authentication methods to unlock the system, and (d) support a “remote unlock” feature, which enables a user to access a user interface provided by server 120 to unlock a particular client from server 120.

Persistence

In an embodiment, agent 110 may check a heartbeat recovery flag in the BIOS and initiate a restore process for the client upon which agent 110 resides if a heartbeat recovery flag so indicates. The restore process can be initiated when the client is booted and/or when the client resumes from sleep mode or hibernation mode. One or more modules of agent 110 may copy a module (referred to as a “FailSafe Windows module” or “FailSafe OS module”) from a secure location (such as BIOS Flash Memory) to an appropriate partition of the operating system of the client (which may be, but need not be, MS Windows from Microsoft Corporation of Redmond, Wash.). The one or more modules may be recovered to a particular partition specified during provisioning or to all applicable partitions. All modules that are recovered may be authenticated before they are loaded and executed.

Implementing Mechanisms

In an embodiment, one or more of clients 102, 104, and 106 may each be implemented using a computer system. FIG. 11 is a block diagram that illustrates a computer system 1100 upon which an embodiment of the invention may be implemented. In an embodiment, computer system 1100 includes processor 1104, main memory 1106, ROM 1108, storage device 1110, and communication interface 1118. Computer system 1100 includes at least one processor 1104 for processing information. Computer system 1100 also includes a main memory 1106, such as a random access memory (RAM) or other dynamic storage device, for storing information and instructions to be executed by processor 1104. Main memory 1106 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 1104. Computer system 1100 further includes a read only memory (ROM) 1108 or other static storage device for storing static information and instructions for processor 1104. A storage device 1110, such as a magnetic disk or optical disk, is provided for storing information and instructions.

Computer system 1100 may be coupled to a display 1112, such as a cathode ray tube (CRT), a LCD monitor, and a television set, for displaying information to a user. An input device 1114, including alphanumeric and other keys, is coupled to computer system 1100 for communicating information and command selections to processor 1104. Other non-limiting, illustrative examples of input device 1114 include a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 1104 and for controlling cursor movement on display 1112. While only one input device 1114 is depicted in FIG. 11, embodiments of the invention may include any number of input devices 1114 coupled to computer system 1100.

Embodiments of the invention are related to the use of computer system 1100 for implementing the techniques described herein. According to one embodiment of the invention, those techniques are performed by computer system 1100 in response to processor 1104 executing one or more sequences of one or more instructions contained in main memory 1106. Such instructions may be read into main memory 1106 from another machine-readable medium, such as storage device 1110. Execution of the sequences of instructions contained in main memory 1106 causes processor 1104 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement embodiments of the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.

The term “machine-readable storage medium” as used herein refers to any medium that participates in storing instructions which may be provided to processor 1104 for execution. Such a medium may take many forms, including but not limited to, non-volatile media and volatile media. Non-volatile media includes, for example, optical or magnetic disks, such as storage device 1110. Volatile media includes dynamic memory, such as main memory 1106.

Non-limiting, illustrative examples of machine-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read.

Various forms of machine readable media may be involved in carrying one or more sequences of one or more instructions to processor 1104 for execution. For example, the instructions may initially be carried on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a network link 1120 to computer system 1100.

Communication interface 1118 provides a two-way data communication coupling to a network link 1120 that is connected to a local network. For example, communication interface 1118 may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 1118 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface 1118 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

Network link 1120 typically provides data communication through one or more networks to other data devices. For example, network link 1120 may provide a connection through a local network to a host computer or to data equipment operated by an Internet Service Provider (ISP).

Computer system 1100 can send messages and receive data, including program code, through the network(s), network link 1120 and communication interface 1118. For example, a server might transmit a requested code for an application program through the Internet, a local ISP, a local network, subsequently to communication interface 1118. The received code may be executed by processor 1104 as it is received, and/or stored in storage device 1110, or other non-volatile storage for later execution.

In the foregoing specification, embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. Thus, the sole and exclusive indicator of what is the invention, and is intended by the applicants to be the invention, is the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction. Any definitions expressly set forth herein for terms contained in such claims shall govern the meaning of such terms as used in the claims. Hence, no limitation, element, property, feature, advantage or attribute that is not expressly recited in a claim should limit the scope of such claim in any way. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. 

What is claimed is:
 1. One or more non-transitory machine-readable storage mediums that store one or more sequences of instructions for securing a client, which when executed, cause: intermittently receiving two or more varieties of location information for the client; and determining a present location of the client by: determining whether any of the two or more varieties of location information were received during an immediately preceding bounded interval of time having a predefined length, determining a weight associated with each of the two or more varieties of location information that were received during the immediately preceding bounded interval of time, and calculating the present location of the client using a weighted arithmetic mean for the two or more varieties of location information that were received during the immediately preceding bounded interval of time.
 2. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the predefined length is configurable.
 3. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the one or more non-transitory machine-readable storage mediums are present in the client.
 4. The one or more non-transitory machine-readable storage mediums of claim 1, wherein calculating the present location of the client further comprises: assessing an accuracy of each of the two or more varieties of location information that were received during the immediately preceding bounded interval of time; and updating the weight associated with at least one of the two or more varieties of information to reflect the accuracy associated therewith.
 5. The one or more non-transitory machine-readable storage mediums of claim 1, wherein calculating the present location of the client further comprises: assessing whether a variety of location information that was received during the immediately preceding bounded interval of time is suggestive of being incorrect; and reducing the weight associated with such suggestively incorrect variety of location information.
 6. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the instructions, when executed, further cause the client to perform an action based on the present location of the client, wherein the action is specified by a security policy stored on the one or more non-transitory machine-readable storage mediums.
 7. The one or more non-transitory machine-readable storage mediums of claim of claim 6, wherein the action is one or more of: disabling the client; degrading the client; requiring authentication from an operator of the client; making a persistent connection to a remote server; executing a command received from the remote server; logging out of an operating system; capturing a webcam picture; capturing a video; and entering an alert mode.
 8. The one or more non-transitory machine-readable storage mediums of claim 6, wherein the action is based on the present location of the client being more than a specified distance from a known location.
 9. The one or more non-transitory machine-readable storage mediums of claim 6, wherein the action is based on the present location of the client being in an unknown area.
 10. The one or more non-transitory machine-readable storage mediums of claim 6, wherein the action is based on the present location of the client being in an unauthorized area.
 11. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the sequence of instructions, when executed, further cause the client to perform an action based on the client not detecting a known network access point.
 12. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the sequence of instructions, when executed, further cause the client to perform an action based on the present location of the client being beyond a specified distance from a wireless device of an authorized user of the client.
 13. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the sequence of instructions, when executed, further cause the client to send details of the present location of the client to a remote server according to a schedule specified by a security policy stored on the one or more non-transitory machine-readable storage mediums.
 14. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the sequence of instructions, when executed, further cause extending the predefined length such that the bounded interval of time encompasses receipt of a more accurate variety of location information than was received during the bounded interval of time prior to the extending thereof.
 15. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the two or more varieties of location information include GPS, Wi-Fi triangulation and IP address.
 16. The one or more non-transitory machine-readable storage mediums of claim 1, wherein the one or more non-transitory machine-readable storage mediums are present in a server that is remote from the client.
 17. The one or more non-transitory machine-readable storage mediums of claim 16, wherein the sequence of instructions, when executed, further cause the server to perform an action based on the present location of the client, wherein the action specified by a security policy stored on the one or more non-transitory machine-readable storage mediums.
 18. The one or more non-transitory machine-readable storage mediums of claim 17, wherein the action is sending a command to the client.
 19. The one or more non-transitory machine-readable storage mediums of claim 16, wherein execution of the one or more sequences of instructions further cause: generating display data which, when rendered, depicts the present location of the client on a map.
 20. The one or more non-transitory machine-readable storage mediums of claim 19, wherein the display data, when rendered, depicts each of the two or more varieties of location information that were received during the interval of time.
 21. The one or more non-transitory machine-readable storage mediums of claim 19, wherein the display data, when rendered, depicts a picture or a video taken by the client.
 22. A method for determining a location of a client, comprising: executing one or more sequences of computer readable instructions to cause: intermittently receiving two or more varieties of location information for the client; and determining a present location of the client by: determining whether any of the two or more varieties of location information were received during an immediately preceding bounded interval of time having a predefined length, determining a weight associated with each of the two or more varieties of location information that were received during the immediately preceding bounded interval of time, and calculating the present location of the client using a weighted arithmetic mean for each of the two or more varieties of location information that were received during the immediately preceding bounded interval of time.
 23. An electronic device configured to determine its own location, comprising: one or more processors; and one or more non-transitory computer readable storage mediums storing one or more sequences of instructions, which when executed by the one or more processors, cause: intermittently receiving two or more varieties of location information for the device; and determining a present location of the device by: determining whether any of the two or more varieties of location information were received during an immediately preceding bounded interval of time having a predefined length, determining a weight associated with each of the two or more varieties of location information that was received during the immediately preceding bounded interval of time, and calculating the present location of the device using a weighted arithmetic mean for each of the two or more varieties of location information that were received during the immediately preceding bounded interval of time. 